Machine for end tapering metal tubing



s Sheet-Sheet 1 o a Q C. L. DEWEY MACHINE FOR END TAPERING METAL TUBINGApril 25, 1944.

Filed Aug. 29, 1942 Aprii 25, 39 (l v 21341232 5 MACHINE FOR ENDTAPERING METAL TUBING Filed Aug. 29, 1942 3 Shams-Sher"; 2

A ril 25, 1944. c. 1.. DEWEY MACHINE FOR END TAPERING METAL TUBING FiledAug. 29, 1942 I s Sheets-Sheet s V chine;

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Patented Apr. 25, 1944 I UNITED- mourns roam 'ra'rnnmo METAL e TUBING T'ciuenee neweimh una August 29, 1842, Serial No. 456,58!

- comma (01.80-13) The machine ointhe present invention is particularlydesigned to step-taper the ends of comparatively short sections of metaltubing of the character employed in the production of propeller shaftsfor use in motor vehicles, or the like, and in which compactness ofstructure and ease and rapidity in operationare highly desirable. -In'the production of shafts of thecharacter in question it isdesirable totaperonly the ends of the shaft so that the range of movement requiredin the operation of the machine is relatively short and in view of thefactithat such shaitsare ordinarily tapered at both ends, it isdesirable to make provision for the simultaneous operation of the twogroups of reducing or deforming elements which move inwardly in unisontoward one anotherand to make provision for rigidly clamping theshait inthe middle so that only the short end portions are exposedthereby sothat-the danger of deflection of the projecting end portions of theshaft may be entirely eliminated by so'mounting the reducing elementsthat they will accurately center the opposite ends or the shait duringthe deforming operation.'

The invention also relates to the means employed for truing the interioroi the extreme ends of the tapered-shaft by the employment oi pilotmandrels which enter the ends ofthe shaft thus smoothing out the insideand accurately centering the ends to align with the medial or undeiormedportion of the tube.

The invention relates specifically to the configuring and mounting of.the forming rolls in such a way as to produce a step-tapered shaft.although the general structure of the machine is such that it may beadvantageously employed with rolls configured to produce a smooth oruninterrupted taper. Further objects and details will appear from adescription of the invention in conjunction with the accompanyingdrawings whereini Figure 1 is a side elevation oi the entire ma- Fig. 2an end view thereof;

Fig. 8 a cross-sectional elevation taken on line HOIFILI;

Fig. a face view'mainly in elevation showing the mounting for theforming rolls and associated Fig. as detail of the 'clamp for engagingthe middle of a tube section.

frame III which is provided along its upper edges withoarriage'slides orrails H which serve to slidably mount duplicate carriages ll each of alike character, so that a description of one will suilice ior both. Each01' the carriages is provided along its edges wlthinwardly extendingguide bars I: which underlie the rails 'l l and' serve to hold thecarriages in position for accurate in and out travel toward one another.As shown, each of the carriages is fed iorwardly or backwardly by a ramll having mounted, thereon a piston I! located within a hydrauliccylinder It, which arrange ment permits the two carriages to be operatedin unison at any desired rate of travel. j.

Each carriage has mounted thereon a riser block H which carries aspindle mounting ll oi cylindrical formation, which spindle mounting isprovided at each ell withroller bearings 58a which provide a mountingfor a tubular spindle l9. which extends centrally through the spindlemounting with its ends projecting outwardly therefrom.

Each spindle is rotated by. a motor-driven sheave 20 which is bolted toasheave coupling 2| whichscrews onto the end of the spindle. Theopposite end of the spindle is screwed into a flanged coupling 22 to theiaceoi which is bolted a circular disk-shaped driving head plate 23.

The hea" plate serves as a carrier for the mounting of three corrugatedtapered rolls 24 the acting suriacesoi which are equally spacedoutwardlyfrom the axis of the clearancespace to be occupied by the tubing and incircumferentially paced relation to one another. Each roll is mountedupon outer and inner roller bearings II and 26 carried by a spindle 21.The outer end of each spindle is socketed within a radially adjustableslide plate 28 having an inwardly projecting overhangi g arm II whichhas bolted thereto an inwardb projecting bracket plate SI which supportsthe inner end oi the spindle which is screwed into a bushing II. Thebracket plate is bolted to the end of the arm 2! bythe headed bolts 32,and the slide plate II is clamped to the head plate by bolts aenteredthrough slots 53 which permit in and out adjustment of therespective slide plates with the corrugated forming rollers carriedthereby. The adjustment oithe platesismaintainedbyscrews a enteredthrough a surrounding flange 3' having the three-armed contour shown inFigure 5.

The bracket plates 3! extend radially inwardasshownlnmlre5withtheirinnerendsfldlacenttotheaxisorthetubewallandroundedto The machine as a whole is mounted upon aIaii'ord adequate clearance.

In order to rigidly sustain and center the tube at a point closelyadjacent to the projecting end undergoing deformation,-a centering ring31 is provided which is carried by a surrounding collar 38 being mountedfor rotation on ball-bearings 39.

The collar is of the triple armed formation shown overhangingarrangement of the roll mountings .and the necessity of maintaining thecentering ring 31 in accurate concentric alignment and at a pointdistant from its base of support.

The head coupling 22 in its center is provided with a boss 42' whichsockets within a center bore 43 in the head plate, and the boss aflordsa socket for a plug 44 carried by ball-bearings 45 which permit thespindle and roll frame ,to rotate without imparting rotation to theplug. The plug has screwed thereinto a center pilot mandrel 46 which isof a ize to fit snugly within the end of th tube when reduced and smoothout or iron out anyburrs or inequalities in the interior of the tube andtrue the tube end to concentric coincidence with the axis of the tubewhich is highly important in the reduction of tubing intended for powertransmissionpurposes.

Each of the forming rolls 24 is of generally tapered formation andprovided with concentric spaced corrugations or circumferential crests41 separated by intervening valleys t8, the crests and valleys of therespective rolls being in common planes so that all will act equallyupon the walls of the tube as the rolls are revolved around the tubeaxis and are rotated by frictional con-- tact with the tube which isheld fixed against both rotary and longitudinal movement during thedeforming operation.

The moddle portion of the tube is held by a clamp secured againstlongitudinal movement and comprising fixed and movable jaw-heads 49 and50 respectively which jaw-heads are provided with opposed V-shapedchannels which. receive serrated jaws adapted to grip the tube walls onfour sides of the tube as shown in. Figure 6.

The fixed jaw head 49 is supported by standards 52 springing upwardlyfrom the frame of the machine and the movabl jaw-head is provided withlugs 53 which mount pintles 54 carried by rods 55 having pistons 56operable within cylinders 51', which permits fluid pressure to beapplied for clamping and releasing the tubes as occasion may require.

In order to feed the tube sections in position to be clamped by thejaws, an inclined stationary runway 58 is provided down which the tubesections roll, the foremost section being restrained by an arresting arm59 recessed at its upper end 30 and pivoted at 8|. A rocking'movement isimparted to the arresting arm 53 by a cylinder and piston arrangementSta, the parts being so arranged that when the lower end of thearresting arm is drawn inwardly as in Figure3, the procession of thetubes will be arrested by contact with the projecting upper prong of thearm 59; but when the lower end of the arm is rocked outwardly, the tubeat the head of the procession will be released to roll into the jaws andthe next tube will be arrested until it is released by a reversemovement of the arm.

As shown, each of the sheaves 20 is operated by a'motor 82 and belt 63,the motor being mounted upon a shelf 64 carried by the carriage. Asshown, the cylinders 51 are suspended from a beam 65 supported bystandards 83 springing upwardly from the base of the machine, and theforming roll and mountings are. shielded and protected by archedhousings .31 as shown in Figure 1'. v i

' Operation With the'carriages equally retracted, as shown in dottedlines in Figure l, to the extent necessary, a tube section is rolledinto place and centrally. clamped by the jaws with its undeformed endsprojecting equally in opposite directions. Power is thereupon applied tothe spindle is which imparts rotation to the head plate 23 and the groupof three rollers carried thereby, which are revolved around the tubeaxis as a center. Concurrently with the revolution of the rolls, thecarriages will begin to move inwardly toward one another until theinnermost ends of the rolls of each group engage the oppositelyprojecting ends of the tube. The innermost corrugations of the threerolls composing a group, being of a minimum diameter andail'ording thewidest clearance, will effect a first step reduction in the tube walland of the tube into short cylindrical portions of progressivelydecreasing diameter with the extreme tip of the tube displaying themaximum reduction. As the carriage advances to bring the endmostcorrugations of the series into acting engagement with the tip end orthe tube, the pilot mandrel 46 will advance, and the interior of thetube will be held in snug frictional contact therewith so that it willbe restrained against rotation while at the same time serving to smoothout and accurately center the minimum end bore of the tube.

The reducing operation causes a redistribution of the metal, resultingin an elongation of the tube or a thickening of the tube wall, or bothof these eflects, but the present invention is not concerned primarilywith these results which are inherent in any tube reducingoperation,howsoever performed.

Ithas been found from experience that the use of circumferentiallycorrugated rolls of the character here shown possesses distinctadvantages in operation, since each of the corrugations aii'ords arounded periphery which advances against the shoulder evolving in thetube wall so that the metal is caused to flow down by minute incrementsin order to escape beneath the rounded periphery of the corrugationwhile the intervening channels ail'ord clearance spaces which break thereducing contacts into .a series of concurrent operations whileaffording clearance behind each corrugation, which assists in theredistributing of the metal and avoids chattering-or. galling of themetalsurfaces which may occur if continuous contacts are maintained.Furthermore the provision ofthe intervening channels provides for thedistribution of a suitable liquid coolant and lubricant which may beforced upon the rolls 24 and around the ends of the tube and onto thepilot mandrel thus lubricating the rolls and holding the tube at a lowtemperature. This permits the cool rolling action of the rolls togreatly increase the tensile strength and hardness of the low carbonsteel strip from which the electrically welded tube was made, it beingadvantageous to increase the strength and stiflness of the step-taperedtube ends when the tube is to be used as an automotive propeller driveshaft or the that the present operation does not require that the tubebe exteriorly reenforced at or near the 31 is not employed for thepurpose of confining the deformation to .the area in contact with theregion of deformation and that the centering ring roll corrugations, butsolely for the purpose of.

accurately holding the tube so that it will be concentrically reduced bythe stepped forming rolls.

After the reduction of the tube has been completed, the tube is removedlaterally by hand or by suitable mechanical means and the operations arepeated while it is not necessary to stop the rotation of the headplates, which need only be drawn back to the extent required tointroduce another tube into position. I I

By revolving the rolls around a stationary tube it is possible to securea high rate of production at lower costs since complications involved inthe chuckingand rotating of the tube are avoided and there is nonecessity for interrupting the continuity of the driving operation inorder to permit the tubes to be introduced and removed.

As shown, the crests of the corrugations on the forming rolls in unisonpresent a straight line of uniform tapering but, it will be understoodcave configuration, or combinations thereof, or

variations in the angle of the taper line without departing from theprinciples of the invention.

Although the present machine has been designed in duplicate to operateupon both ends of a tube section simultaneously, it is not theintention, unlessotherwise indicated, to limit the profor concurrentlytapering the for engaging the medial portion of a section of tubing inposition to allow the ends of the tube section to project opp tely outward from the clamp, duplicate sets of reducim vp r e. the

. that the crest lines may assume a convex or con- .of the respectiveshafts, a spindle for each set of rolls and means for rotating the Vmountings to cause the rolls to revolve around an axis concentric withthe tube axis concurrently with the advance of the carriage toprogressively taperthe end of tube, and feeding devices oif-setlaterally from the clamp for inwardly delivering the tubes laterally andsingly into the bite of the clamp.

2. In a machine for tapering the ends of tubing, the combination of aclamp for eng n a tube at a point remote from the end to be tapered, aplurality of reducing rolls of progressively increasing diameter in thedirection away from the end of the tube to be presented for tapering,the acting surfaces of the rolls being outwardly spaced from the axialcenter line of the tube to concurrently engage the tube wall incircumferentially spaced relation around the tube axis, a shaft forrotatably mounting each of the rolls, ahead plate and inwardly extendingarms secured thereto for supporting the opposite ends carriage, and apilot mandrel concentric with the tube axis and entered through the headplate in position to enter the reduced end of the tube to true andsmooth the same.

3. In a machine for tapering the ends of tubing, the combination of aclamp for engaging a tube at a point remote from the end to be tapered,a plurality of reducing rolls of progressively increasing diameter inthe direction away from the end-of the tube to be presented for taactingsurfaces of the rolls being outwardly spaced from the axial center lineof the tube to concurrently engage the tube wall in circumferentiailyspaced relation around the tube axis, a shaft for rotatably mountingeach of the rolls, a head plate and inwardly extending arms securedthereto for supporting the opposite ends secured to the head plate andoutwardly extending therefrom V and power means for rotating thespindle, a cena section of tubing, the combimechanisms each carried by acarriage and power means for oppositely advancing the carriages inunison inwardly-toward the projecting ends of the tubing and retractingthe carriages in unison therefrom, each carriage supporting thereon aplurality of forming rolls of progressively increasing diameter in thedirection away from the proximate end of the tube presented fortapering, the acting surfaces of the rolls being outwardly spaced fromthe axial centerline of the tube to concurrently engagethe tube wallalong longitudinally converging lines 'in circumferentiaily spacedrelation around the tube axis, a mounting tering ring adapted tosurround the tube inward- 1y beyond the region contacted by the rollsand means for supporting the ring from the head plate, a carriage formounting the spindle and parts carried thereby, means for advancing andretracting the carriage, and a pilot mandrel concentric with the tubeaxis and entered through the head plate in position to enter the reducedend of the tube to true and smooth the same.

4. In a machine for tapering the ends of tubing, the combination of aclamp for engaging a tube at a point remote from the end to be tapered,a phn'ality of reducing rolls of progr ively increasing diameter in thedirection away from the end of the tube to be presented for tapering,the acting surfaces of the rolls being outwardly spaced from the axialcenter line of the tube to concurrently engage the tube wall incircumferentially spaced relation around the tube axis, a shaft forrotatably mounting each of the rolls, a head plate and inwardlyextending arms secured thereto for supporting the opposite ends of therespective shafts, a spindle secured to the head plate and outwardlyextending therefrom and power means for rotating the spindle, acentering ried thereby, and means for advancing and retracting thecarriage. 5. In a machine for concurrently tapering the opposite ends ofa section of tubing, the combination of a clamp for engaging the medialportion of a section of tubing in position to allow the ends of the tubesection to project oppositely outward from the clamp, duplicate sets ofreducing mechanisms each carried by a carriage and power means foroppositely advancing the carriages in unison inwardly toward theprojecting ends of the tubing and retracting the carriages in unisontherefrom, each carriage supporting thereon a plurality offorming rollsarranged in circumferentially Spaced relation around the tube axis andpresenting their acting surfaces in progressively closer relation tosaid axis from the receiving to the discharge ends of the rolls; amounting for each set of rolls and means for rotating the mountingstocause the rolls to revolve around said axis concurrently with theadvance of the carriage to progressively taper the end of the tube, andfeeding devices for delivering the tubes laterally and singly into thebite of the clamp.

6. In a machine for tapering the ends of tubing, the combination of aclamp tor engaginga tube at a point remote from the end to be tapered, aplurality of reducing rolls standing in circumferentially spacedrelation around the tube axis and presenting their acting surfaces inprogressively closer relation to said axis from the receiving to thedischarge ends or said rolls, a shaft for rotatably mounting each 01'the rolls, a head plate and inwardly extending arms secured thereto forsupporting the opposite ends of the respective shafts, a spindle securedto the head plate and outwardly extending therefrom, and power means forrotating the spindle, a carriage for mounting the spindle and partscarried thereby, means for advancing and retracting the carriage, and apilot mandrel concentric with the tube axis and entered through the headplate in position to enter the reduced end of the tube to true andsmooth the same.

CLARENCE L. DEWEY.

